Morgan County climate

Morgan County Frost Dates and Growing Season

NOAA 1991-2020 normals for Watkinsville 5 Sse, 23.4 km from Morgan County, elevation 741 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Watkinsville 5 Sse. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around March 24 and the first fall freeze around November 12, a growing season of about 234 days.

Median at 36°F
last April 7, first November 1
Median at 32°F
last March 24, first November 12
Median at 28°F
last March 5, first November 28

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FApr 22Apr 18Apr 14Apr 11Apr 7Apr 3Apr 1Mar 26Mar 20
32°FApr 12Apr 5Apr 2Mar 28Mar 24Mar 19Mar 15Mar 10Mar 1
28°FMar 28Mar 21Mar 15Mar 11Mar 5Feb 28Feb 24Feb 17Feb 6
24°FMar 14Mar 5Feb 28Feb 21Feb 15Feb 8Feb 2Jan 28Jan 20
20°FMar 1Feb 18Feb 8Feb 2Jan 29Jan 24Jan 17Jan 9Jan 2
16°FFeb 14Feb 3Jan 29Jan 25Jan 21Jan 16Jan 11Jan 6Dec 30

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FOct 18Oct 23Oct 27Oct 29Nov 1Nov 3Nov 5Nov 9Nov 16
32°FOct 31Nov 3Nov 6Nov 9Nov 12Nov 16Nov 19Nov 25Dec 2
28°FNov 10Nov 15Nov 19Nov 24Nov 28Dec 1Dec 6Dec 14Dec 25
24°FNov 21Nov 30Dec 4Dec 9Dec 17Dec 23Dec 29Jan 4Jan 13
20°FDec 6Dec 15Dec 24Dec 30Jan 2Jan 7Jan 12Jan 19Jan 31
16°FDec 21Dec 30Jan 2Jan 6Jan 10Jan 15Jan 20Jan 25Feb 2

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F231223217213208204200194187
32°F263255247241234229223217207
28°F301288280273267261253246238
24°F339328317309302295288279267
20°F365357348339334328319309299
16°F365365365365361351343335323

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
98% of years
20°F or colder
86% of years
16°F or colder
52% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
2,789
Cooling degree days, base 65°F
1,694
Growing degree days, base 40°F
8,163
Growing degree days, base 45°F
6,539
Growing degree days, base 50°F
5,069
Growing degree days, base 55°F
3,759
Growing degree days, base 60°F
2,633

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January653049
February494168
March3558174
April15537339
May35165595
June1337786
July0439904
August0405869
September8241682
October12756399
November3756140
December587162

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 23.4 km from Morgan County. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USW00063850 (Watkinsville 5 Sse). Public domain.